The ESM is a vacuum actuated EGR system that obtains engine vacuum from a dedicated vacuum harness linking the intake manifold vacuum port to a vacuum supply port on the ESM. Conventional vacuum driven applications obtain source vacuum from the intake manifold pick-of-port and link to a device through conventional vacuum harness technology. Two connections to the intake vacuum port are required with the conventional configuration, one dedicated line for manifold absolute pressure (MAP) and one for an EGR vacuum regulator (EVR).
The conventional ESM system has field issues including vacuum harness damage, connection integrity, part robustness, system cost and ease of assembly. These issue are influencing ESM customers to investigate/source competing electric/solenoid driven EGR systems that do not require vacuum to operate.
Thus, there is a need to provide a robust and cost-effective ESM.